Frozen talks over fusion reactor warm up

 作者:富矮回     |      日期:2019-03-15 05:03:01
By Maggie McKee Europe and Japan have taken a significant step towards finalising the highly contentious plan to build the world’s largest nuclear fusion facility, thawing negotiations that have been frozen for 18 months. But the countries have not yet settled the most crucial question of where to build the reactor. The ambitious project, called ITER – International Thermonuclear Experimental Reactor – aims to lay the groundwork for using nuclear fusion as an inexhaustible and clean energy source. But progress on ITER ground to a halt in December 2003 because its six member parties could not agree on where to locate the premier facility. The EU, China and Russia lobbied for Cadarache in France, while the US, South Korea and Japan supported the Japanese town of Rokkashomura. Both France and Japan continue to vie for the project’s main site. But representatives from the EU and Japan apparently thrashed out a deal in Geneva, Switzerland on 5 May outlining the responsibilities of the country that will host ITER and those of the country that will miss out on the reactor. The details have not been officially released, but some were provided by recent Japanese media reports – details that had been previously mooted. In the agreement, the host would cover 50% of the construction costs – estimated at between $5 billion and $10 billion – while the non-host and the other four parties would each cover 10%. Also, the non-host would itself play host to a related facility – estimated to cost between $1 billion and $2 billion – to test how various materials stand up to bombardment by the high-energy neutrons produced in fusion reactions. And the non-host country would be allowed to send 40 researchers to the facility – making up 20% of its work force. “We see the recent talks as very optimistic and moving the process forward,” EU spokesperson Antonia Mochan told New Scientist. “But we’ve still got a way to go.” Indeed, recent comments by French president Jacques Chirac asserting that ITER would almost certainly be built in France inflamed Japanese officials, who vehemently denied they had given up their bid. But the recent crossfire may actually be a positive sign, says Raymond Fonck, a physicist at the University of Wisconsin in Madison who has reviewed ITER for the US National Academy of Sciences. It suggests the two countries “are talking and bartering back and forth,” he says. “That’s very encouraging.” The initial agreement hammered out by the two countries will be ratified by the six parties at a ministerial meeting in June, according to French research minister Francois d’Aubert, who says a site agreement could follow shortly thereafter. “There is a lot of hope there will be a decision in June or July of this year,” Fonck told New Scientist. “But who will win? Just place your bets.” ITER would work by heating isotopes of hydrogen to hundreds of millions of degrees, creating a plasma of charged particles. Confined by magnetic fields in a doughnut-shaped machine called a tokamak, the particles would collide and fuse, producing high-energy helium nuclei and neutrons. The uncharged neutrons would escape the tokamak, creating heat that could be used to generate electricity. But the positively charged helium nuclei would be trapped by the magnetic fields and would help sustain further fusion reactions. More on these topics: